CONSTANT TRANSCONDUCTANCE AMPLIFIER USING BIAS CURRENT CONTROL

The present invention relates to a constant transconductance amplifier using bias current control, which comprises: a replica amplifier being identical to an external transconductance amplifier, receiving a first reference voltage and a second reference voltage, and outputting an output voltage (I_Replica) corresponding to a voltage difference by its own transconductance; a current source supplying a constant current (I_Constant) for changes of a process, voltage, and temperature; an OP amplifier receiving a voltage generated by the output voltage (I_Replica) and resistance (R_A, R_B) having the same resistance value as the constant current (I_Constant) to generate a control voltage (V_Control); and a bias current control circuit adjusting a bias current (I_SS) in response to the voltage output from the OP amplifier and outputting the bias current to the replica amplifier and the external transconductance amplifier. Therefore, it is possible to maintain a constant transconductance without fuse tuning by regulating the bias current of the transconductance amplifier and control the transconductance more accurately using an analog method.